Ant Neighbors: Pogonomyrmex rugosus and Messor pergandei

A friend is building a new house and he wanted to know about the ant colonies he found in his yard.

Photograph by Bill Webster

These shiny black ants are Messor pergandei (also seen in the literature as Veromessor.) They are a type of harvester ant, which means they collect, process, and store seeds as their main food source (See previous post).

Nearby was another ant colony.

Photograph by Bill Webster

Although these ants look similar superficially to those above, on closer inspection their bodies are dark maroon-red rather than black, particularly in the mid section. They also have fine parallel grooves on their heads. Theses ants are harvesters known as Pogonomyrmex rugosus.

Although both these species harvest similar types of seeds, it is not uncommon to find them living near each other. Robert Johnson (1992) suggests that they may segregate over broad regions based on soil texture, but coexist together in regions of overlap.

Some of Bill's earlier photographs showed the ants had placed a ring of wood fragments from construction as a barrier around their colony. It would be interesting to see whether they were reacting to conspecific colonies or those of other species.